Biopsychology Flashcards
What is the nervous system?
Consists of the central nervous system and the peripheral nervous system.
Communicates using electrical signals.
What is the central nervous systen?
Consists of the brain and spinal cord and is the origin of all complex commands and decisions.
What is the peripheral nervous system?
Sends information to the central nervous system from the outside world, and transmits messages from the central nervous system to muscles and glands in the body.
What is the somatic nervous system?
Transmits information from receptor cells in the sense organs to the central nervous system. It also recieves information from the central nervous system that directs muscles to act.
What is the autonomic nervous system?
Transmits information to and from internal bodily organs. It is autonomic as the system operates involuntarily.
What are the two main divisions of the autonomic nervous system?
Sympathetic and parasympathetic.
What is the nervous system based on?
Electrical and chemical signals.
What are the two main functions of the nervous system?
- To collect, process and respond to information in the enrivonment.
- To co-ordinate the working of different organs and cells in the body.
What is the brain?
The centre of all conscious awareness.
What is the brain divided into?
Two hemispheres.
What is the spinal cord?
An extension of the brain that passes messages to and from the brain and connects nerves to the peripheral nervous system.
It is also responsible for reflex actions.
What does the sympathetic nervous system do?
Speeds activity up.
What does the parasympathetic nervous system do?
Slow activity down.
What is the endocrine system?
One of the body’s major information systems that instructs glands to release hormones directly into the bloodstream.
These hormones are carried towards target organs in the body.
Communicates via chemicals.
What is a gland?
An organ in the body that synthesises substances such as hormones.
What is a hormone?
A biochemical substance that circulates in the blood but only affects target organs. They are produced in large quantities but disappear quickly.
Their effects are very powerful.
What is the fight or flight response?
The way an animal responds when stressed.
The body becomes physiologically aroused in readiness to fight an aggressor, or in some cases flee.
What is adrenaline?
A hormone produced by the adrenal medulla which is part of the human body’s immediate stress response system.
Adrenaline has a strong effect on the cells of the cardiovascular system.
Name four effects of adrenaline.
Sweating
Increased heart rate
Contracting blood vessles
Dilating air passages.
How do hormones get into the bloodstream?
Secretion.
What are the 7 parts of the endocrine system?
Hypothalamus
Pituitary gland
Thyroid gland
Adrenal gland
Pancreas
Ovaries (female)
Testes (male)
Which two systems work together in a stressful event?
Endocrine system and the autonomic nervous system.
What happens when a stressor is perceived?
The hypothalamus activates the pituitary gland and this triggers activity in the sympathetic branch of the autonomic nervous system.
The autonomic nervous system changes from the parasympathetic state to the sympathetic state.
Is the fight or flight response immediate and automatic?
Yes
What happens once a threat is passed?
The parasympathetic nervous system returns the body to its natural resting state.
How is adrenaline released?
The hypothalamus activates the sympathetic branch of the autonomic nervous system through the SAM pathway, ACTH is released from the pituitary gland which then signals the adrenal medulla to secrete adrenaline and noradrenaline.
What is a neuron?
The basic building blocks of the nervous system, neurons are nerve cells that process and transmit messages through electrical and chemical signals.
What are sensory neurons?
They carry messages from the peripheral nervous system to the central nervous system.
They have long dendrites and short axons.
What are relay neurons?
They connect the sensory neurons to the motor or other relay neurons.
They have short dendrites and short axons.
What are motor neurons?
They connect the central nervous system to effectors such as muscles or glands.
They have short dendrites and long axons.
How do neurons transmit signals?
Electrically or chemically
What is the cell body?
Contains a nucleus, which contains the genetic material of the cell.
What is a dendron?
Dendrons transmit nerve impulses towards the cell body.
What is a dendrite?
The end branches of dendrons which recieve nerve impulses.
What is an axon?
An axon carries impulses away from the cell body down the length of the neuron.
What is the myelin sheath?
A fatty layer which covers the axon and protects it and speeds up electrical transmission of the impulse.
What would happen if the myelin sheath was continuous?
It would have the reverse effect and slow down the electrical impulse.
What are nodes of ranvier?
Gaps that segment the myelin sheath amd spped up the transmission of the impulse by forcing it to ‘jump’ across the gaps along the axon.
What are terminal buttons?
The end of the axon are terminal buttons which communicate with the next neuron in the chain across a gap known as the synapse.
What are clusters of sensory neurons called?
Ganglia and are found in the PNS.
What % of neurons do relay neurons make up?
97% and most are found in the brain.
Describe electrical transmission withtin neurons.
- When a neuron is in a resting state, the inside of the cell is negatively charged compared to the outside.
- When a neuron is activated by a stimulus, the inside of the cell becomes positively charged for a split second causing an action potential to occur.
- This creates an electrical impulse that travels down the axon towards the end of the neuron.
What is synaptic transmission?
The process by which neighbouring neurons communicate with each other by sending chemical signals across the synapse that separates them.
What is a neurotransmitter?
Brain chemicals released from synaptic vesicles that relay signals across the synapse from one neuron to another.
They can be classified as either excitatory or inhibitory.
What is excitation?
When a neurotransmitter such as adrenaline, increases the positive charge of the postsynaptic neuron. This increases the likelihood that the postsynaptic neuron will pass on the electrical impulse.